There is disclosed in European patent specification No. 89141A of Sept. 21, 1983 a cathode having a nickel or nickel-coated iron substrate and a catalytically active coating containing a powder mixture of an intermetallic AB.sub.5 compound and nickel. The coating was applied from an aqueous polysilicate slurry and was sintered in hydrogen to create a metallurgical bond to the substrate. This cathode exhibits excellent electrocatalytic activity. However, the following drawbacks were encountered during manufacture of cathodes of industrial size. First manufacturing costs were high, primarily because of the high temperature, hydrogen atmosphere sintering step. Secondly, the cathode substrate was extremely soft after heat treatment. Finally, the high sintering temperatures and times required to produce a coating with good abrasion resistance had an adverse effect on catalytic activity.
In U.S. Pat. No. 4,410,413 it is disclosed that a non-spinel oxide is formed in a plasma sprayed coating of nickel on an electrode substrate and that this non-spinel oxidic coating has good electrocatalytic properties for evolution of hydrogen when it is exposed in situ to cathodically produced hydrogen.